KR101132476B1 - Network apparatus for quality of iptv service - Google Patents

Abstract

The present invention relates to a network device having a function of guaranteeing the quality of an IPTV service. In accordance with a request for an IPTV service from an IPTV terminal, the present invention relates to a port for transmitting the IPTV service after checking a transmission specification (bandwidth, frame rate, etc.) of a corresponding channel. By determining whether to provide an IPTV service in consideration of a free bandwidth of a matching queue, a network device having a quality guarantee function of an IPTV service for providing a stable IPTV service is provided.

To this end, the present invention provides a network device comprising: queue management means for managing an extra bandwidth of a queue corresponding to each port number; Packet classification means for detecting a port number in response to receiving a service request packet from an IPTV terminal and transmitting the detected port number together with the service request packet; Protocol processing means for detecting a destination address and a source address from the service request packet received from the packet classification means and delivering the received destination number together with the received port number; And an admission control means for determining whether to provide a service by comparing the bandwidth of the service requested by the IPTV terminal after checking the free bandwidth of the queue corresponding to the port number received from the protocol processing means.

IGMP, IPTV, Admission Control, Policy Control, Queue, CIT (Channel Information Table)

Description

NETWORK APPARATUS FOR QUALITY OF IPTV SERVICE}

The present invention relates to a network device having a quality assurance function of an IPTV service, and more particularly, to a network device for performing admission control and bandwidth reservation for an IPTV service based on an Internet Group Management Protocol (IGMP).

In general, an IPTV (Internet Protocol Television) service refers to a service that provides information service, video content, and broadcasting to a television receiver using high-speed Internet.

This IPTV service is a type of digital convergence in that it is a convergence of the Internet and the television. The difference from the Internet TV is that it uses a television receiver instead of a computer monitor and a remote controller instead of a mouse.

And to use IPTV service, only television receiver, set-top box and internet need to be connected. In other words, you can add a set-top box or a dedicated modem to your television and turn it on just as you turn it on. Therefore, even a person unfamiliar with a computer can use the remote control to receive various contents and additional services provided by the Internet such as watching movies, home shopping, home banking, online games, and MP3s as well as searching the Internet.

This IPTV service is not different from general cable broadcasting or satellite broadcasting in that it provides broadcasting contents including video, but it is a feature that bidirectionality is added. That is, unlike general public broadcasting, cable broadcasting or satellite broadcasting, viewers can select and watch only the programs they want to watch at their convenient time. Therefore, the initiative of TV broadcasting is passed from the broadcaster or the broadcaster to the viewer.

Currently, some countries, including Hong Kong, Italy and Japan, offer IPTV services, but this is an early stage globally. In Korea, telecom operators are actively making inroads into IPTV services to take full advantage of their existing infrastructure and enjoy a range of economic benefits.

1 is a configuration diagram of an embodiment of a general IPTV service system.

As shown in FIG. 1, the IPTV service system includes at least one Internet Group Management Protocol (IGMP) client (IPTV terminal) including a TV receiver and an IP set-top box, and processes the IGMP clients to receive IPTV services through the Internet. The state consists of network equipment (tangential switch, L3 switch, IPTV distribution switch).

In this case, the network equipment is a host (CPU) that processes IGMP requests from IGMP clients (subscribers), a packet transmission / reception function that is connected to the IGMP client and the Internet, respectively, and is connected to a higher-level IGMP network equipment to perform data transmission / reception functions. It consists of a receiving unit.

Each host and packet transmit / receive unit has a multicast table that stores channel information (group IP or group Mac) and IGMP client information for each channel, and creates / generates a multicast table as a result of processing IGMP. It modifies / deletes and generates appropriate IGMP packets and sends them to upper IGMP network equipment if necessary.

Since this IGMP processing in IGMP network equipment is completely host dependent, IGMP network equipment provides a way to reduce the number of IGMP packets sent to higher network equipment. In other words, the host load of the upper IGMP network equipment is reduced by sending only the necessary or host-generated IGMP messages among the IGMP packets transmitted from the IGMP client to the upper IGMP network equipment.

Hereinafter, a signal processing process (IPTV service processing process) in the conventional IGMP network equipment will be described.

First, an IGMP client sends an IGMP Membership Report (hereinafter referred to as an IGMP report) message to a packet transmission / reception unit of an IGMP network device in order to watch an arbitrary channel Ch10.

Subsequently, the packet transmission / reception unit of the IGMP network equipment transmits the received IGMP Report message to the host.

Then, the host determines whether the channel requested by the IGMP client through the IGMP Report message is registered in the multicast table.

If the channel requested by the IGMP client is not registered in the multicast table, the host registers the channel and IGMP client information requested by the IGMP client in the multicast table.

The host also updates the multicast table of the packet transmit / receive unit to correspond to changes in the host.

The host then sends an IGMP report to the upper IGMP network device via the packet transmit / receive unit. Here, the host may transmit the modified IGMP Report message as it is or received from the IGMP client.

Meanwhile, when the upper IGMP network device receives an IGMP Report message requesting an arbitrary channel from the lower IGMP network device, it determines whether a channel corresponding to the IGMP Report message is received from an IPTV broadcasting station.

If the requested channel is provided from an IPTV broadcasting station through an IGMP Report message, the upper IGMP network equipment duplicates the IPTV broadcast stream of the requested channel and transmits the packet to the packet transmitting / receiving unit of the lower IGMP network equipment.

If not, the upper IGMP network device interoperates with a multicast routing protocol such as PIM (Protocol Independent Multicast) to receive the corresponding IPTV broadcast stream or sends an IGMP message to its upper network device again to request the IPTV broadcast stream. In the end, it transmits to the packet transmission / reception unit of the lower IGMP network equipment.

Then, the packet transmitting / receiving unit of the lower IGMP network equipment transmits an IPTV broadcast stream which is a channel requested by the IGMP client that has transmitted the IGMP Report message.

On the other hand, if the channel requested by the IGMP client is registered in the multicast table of the packet transmission / reception unit, and the IGMP client is also registered in the channel, the host updates the IGMP client information in the channel registered in the multicast table. And exit.

However, if the channel requested by the IGMP client is registered in the multicast table of the packet transmission / reception unit, and the IGMP client is not registered in the channel, the host sends the IGMP client information to the channel registered in the multicast table. In addition, this content is reflected in the packet transmission / reception unit. Thereafter, the IPTV stream of the channel is duplicated and transmitted to the IGMP client.

Such conventional network equipment provides a channel requested by a user by determining whether to provide a service for a corresponding channel as mentioned above, without considering a maximum transmission bandwidth of a queue matched to a port for transmitting an IPTV service. Therefore, when the bandwidth of all the channels provided exceeds the maximum transmission bandwidth of the queue, there is a problem in that the quality of all real-time IPTV services is deteriorated, so that normal IPTV services cannot be provided.

It is a problem of the present invention to solve the problems of the prior art as described above.

Therefore, in accordance with the present invention, when IPTV service is requested from an IPTV terminal, IPTV is checked in consideration of a transmission specification (bandwidth, frame rate, etc.) of a corresponding channel, and then considering an available bandwidth of a queue matching the port for transmitting the IPTV service. The purpose of the present invention is to provide a network device having a function of guaranteeing the quality of an IPTV service for providing a stable IPTV service by determining whether to provide a service.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

을 만족하는 경우 상기 IPTV 단말로부터의 서비스 요청을 수락하고, 만족하지 않는 경우 상기 IPTV 단말로부터의 서비스 요청을 거절한다. 여기서, BQ_req는 CIT에서 확인된 요청 서비스의 전송 대역폭, BQ_avail은 해당 큐의 여유 대역폭, BQ_max는 해당 큐에서 사용 가능한 최대 전송 대역폭,

는 해당 큐의 현재 예약된 서비스의 대역폭, BQ_lim은 일반 서비스 트래픽의 전송을 위한 최소 대역폭을 나타낸다.An apparatus of the present invention for achieving the above object is a network device, comprising: queue management means for managing an extra bandwidth of a queue corresponding to each port number; Packet classification means for detecting a port number in response to receiving a service request packet from an IPTV terminal and transmitting the detected port number together with the service request packet; Protocol processing means for detecting a destination address and a source address from the service request packet received from the packet classification means and delivering the received destination number together with the received port number; And an admission control means for determining whether to provide a service by comparing the bandwidth of the service requested by the IPTV terminal after checking the free bandwidth of the queue corresponding to the port number received from the protocol processing means. At this time, the admission control means,

If the service provider satisfies the request for service from the IPTV terminal, the service service request from the IPTV terminal is rejected. Where BQ_req is the transmission bandwidth of the request service identified in the CIT, BQ_avail is the free bandwidth of the queue, BQ_max is the maximum transmission bandwidth available in the queue,

Is the bandwidth of the current reserved service of the queue, BQ_lim represents the minimum bandwidth for the transmission of general service traffic.

The present invention reserves a flow of a real-time IPTV service using IGMP, limits the provision of a service when a service is requested in a queue corresponding to a transport port of the flow in excess of a threshold bandwidth, and is being transmitted in real time. Provides stable.

Therefore, the present invention protects the real-time IPTV service traffic based on policy control and acceptance control using IGMP, and if the possibility of congestion is high when applying for the service, it can maintain the quality of the IPTV service by refusing to accept the service.

The present invention as described above, after receiving the IPTV service request from the IPTV terminal checks the transmission specifications (bandwidth, frame rate, etc.) of the channel and then the available bandwidth of the queue (Queue) matching the port for transmitting the IPTV service In consideration of whether or not to provide IPTV service, there is an effect that can provide a stable IPTV service.

In addition, the present invention uses the IGMP already applied without the introduction of a new protocol, compared to the bandwidth protection technology using other resource reservation protocols such as RSVP, there is no need to change the structure of the terminal and server.

In addition, the present invention by using the IGMP itself as a bandwidth protection protocol and the admission control protocol, the route setting and reservation procedure by the other reservation protocol is omitted, the channel switching time of the IPTV is not increased does not increase the user convenience There is.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In the present invention, the network device includes, for example, a tangential switch, an L3 switch, an IPTV distribution switch, a router, and the like.

2 is a block diagram of an embodiment of a network device having a function of guaranteeing quality of an IPTV service according to the present invention.

As shown in FIG. 2, a network device having a function of guaranteeing the quality of an IPTV service according to the present invention includes a queue manager 20 for managing an extra bandwidth of a queue corresponding to each port number, and a service request packet from an IPTV terminal. The packet classification unit 21 for detecting the port number and transmitting the service request packet to the protocol processing unit 22 according to the reception, and the destination address and the source address in the service request packet received from the packet classification unit 21. Detects and transmits the free bandwidth of the queue corresponding to the port number received from the protocol processing unit 22, and the protocol processing unit 22 for delivering to the acceptance control unit 23 with the received port number of the queue management unit 20 After confirming through), it is compared with the bandwidth of the service requested by the IPTV terminal and accepts to determine whether to provide a service according to the result. And a fisherman 23.

Additionally, the network device further includes a platform interworking unit, a policy control unit, a packet processing unit, a traffic measuring unit, a flow registration unit, a scheduler, and a real time monitoring unit.

Here, the platform interworking unit receives a channel information table (CIT) necessary for resource reservation from the CIT / policy control server, and transmits a service rejection message to the admission control server when the resource reservation fails.

In addition, the packet processing unit may manipulate the head field of the packet or execute the preprocessing table to perform processing such as filtering, priority remarking, NAT, VLAN, reservation tag insertion, etc., which the packet is given by the policy control unit with reference to the lookup table. To create the post-processing table.

The packet processor may refer to the lookup table based on a preprocessing table in the internal information table generated by the packet classifier 21 to classify the packet, and if the priority specified in the packet and the lookup table is different, the packet may be the priority of the lookup table. Mark the port to be forwarded, record the port to be forwarded, insert and delete the VLAN that requires operation, insert the tag for whether to insert the reservation tag to manage as a virtual queue for bandwidth protection, whether to execute the real-time monitoring, and to measure the traffic. Create a processing table.

In addition, the traffic measuring unit measures the traffic volume of the registered service.

That is, when the traffic measurement tag is inserted into the post-processing table, the traffic measuring unit calculates the transmission bandwidth in real time by measuring the traffic speed of the corresponding service.

Using the calculated transmission bandwidth, the protocol processing unit 22 updates the corresponding bandwidth field of its multicasting table, the acceptance control unit 23 updates the corresponding bandwidth field of its own admission control table, and the flow registration unit Update the corresponding bandwidth field of the lookup table.

In addition, the scheduler schedules and transmits a packet by applying a conventional strict priority queuing (SPQ) or a decreit weighted round robin (DWRR) method.

In addition, the real-time monitoring unit monitors the traffic situation in real time.

Meanwhile, in the present invention, the packet classifier 21 transmits a port number for which a service is requested to the protocol processor 22 by referring to the multicasting IP address and IP layer protocol type field of IGMP.

In addition, the packet classification unit 21 generates and inserts a preprocessing table containing the packet classification result in the accepted IPTV service packet. At this time, the preprocessing table includes information indicating on which port the result classified by the packet classification rule is input, the MAC address, the IP address, the TCP / UDP address, the VLAN ID, the priority, and the like.

In addition, the admission control unit 23 checks the bandwidth of the channel requested by the IPTV terminal with reference to the CIT (Channel Information Table), and then checks the free bandwidth of the queue corresponding to the port number through the queue management unit 20, If the following Equation 1 is satisfied, the service request is accepted.

In this case, the CIT is a network-channel information table corresponding to an EPG (Electronic Program Guide), and includes a destination hydrogen corresponding to a service channel, a transmission bandwidth, a frame rate, and a channel attribute of a program according to time. At this time, the CIT includes channel information for the network device to recognize the network characteristics of the IPTV service program and is provided by the CIT / policy control server.

BQ_req: Transmission bandwidth of requested service identified in CIT

BQ_avail: Free bandwidth for this queue

BQ_max: Maximum transmission bandwidth available for this queue

: 해당 큐의 현재 예약된 서비스의 대역폭

: Bandwidth of the current scheduled service for this queue

BQ_lim: Minimum bandwidth for transmission of general service traffic (determined by policy)

In addition, when accepting the service request from the IPTV terminal, the admission control unit 23 registers the network address of the channel in the admission control table, and notifies the protocol processing unit 22 to register it in the multicasting table. That is, the acceptance control unit 23 registers and manages the request address, the reception and transmission port, the transmission speed, and the like of the channel accepted for each port in the admission control table.

At this time, when the service request from the IPTV terminal satisfies [Equation 1], the admission control unit 23 performs general traffic without quality assurance in order to protect bandwidth of all channels registered in the admission control table. It can also be limited as shown in [Equation 2].

BQ_rate_limit: Maximum transfer bandwidth that can be limited

BQ_max: Maximum transmission bandwidth available for this queue

: 해당 큐의 현재 예약된 서비스의 대역폭

: Bandwidth of the current scheduled service for this queue

B_mar: Minimum free transmission bandwidth required for secure traffic control

BQ_lim: Minimum bandwidth for transmission of general service traffic (determined by policy)

However, due to the characteristics of multicasting traffic, when the sum of the transmission bandwidths of the channels is obtained, the bandwidth is managed for each service destination address. That is, even though there are many terminals with the same destination address receiving the same service, since the actual multicasting traffic is the same as one service band, the bandwidths of channels having different destination addresses are calculated by summing the transmission bandwidths.

On the other hand, the acceptance control unit 23 does not accept the service request when the free bandwidth of the corresponding queue determined by the queue management unit 20 is smaller than the bandwidth of the request service as shown in Equation 3 below.

In addition, the acceptance control unit 23 notifies the platform interworking unit of the service rejection message including the address of the request for the service, in order to notify the service provider of the IPTV terminal requesting the service.

Then, the platform interworking unit transmits a service denial message to the admission control server.

Then, the admission control server notifies the service requesting terminal of the service rejection message notifying that the service cannot be received due to the traffic situation of the network.

The IPTV terminal receiving the service rejection message displays the message on the screen to inform the user that the service is not available.

On the other hand, when the acceptance control unit 23 accepts the service request, the protocol processing unit 22, when the destination address to be subscribed to the multicasting table is registered, the source address and the source port to be forwarded to the destination address through the flow registration unit. Add At this time, if the service is already forwarded to the same port, only the address is additionally registered.

In addition, the protocol processing unit 22, if the destination address to subscribe to the multicasting table is not registered, the destination address and source address, the corresponding source port to be forwarded, bandwidth, priority, whether or not bandwidth protection, real-time monitoring or not, traffic Register in the multicasting table with a tag that specifies the action such as measurement or not.

Hereinafter, the queue manager 20 will be described in detail with reference to FIG. 3.

As shown in FIG. 3, the queue manager 20 simplifies queue management by effectively managing the traffic of the IPTV channel and the unreserved general traffic as a virtual queue, and effectively protects the bandwidth of the IPTV channel.

The packet processing unit inserts a reservation tag specifying that bandwidth should be protected by the admission control. Based on this tag, the queue management unit 20 manages the IPTV service traffic as virtual queue 1 and manages general traffic as virtual queue 0. Manage with.

Therefore, the queue manager 20 limits the processing speed of the virtual queue 0 to protect the transmission bandwidth of the virtual queue 1. In this case, the virtual queues are two buffers having a constant size that temporarily store packets before they are put in the final queue, and are designed to limit bandwidth entering the queue. If necessary, several virtual queues can be managed according to the purpose of the service.

That is, the queue manager 20 limits the bandwidth by shaping the virtual queue 0 that is bandwidth-limited.

In addition, the queue manager 20 checks whether the bandwidth measured by the traffic measuring unit is smaller than the free bandwidth and forwards it through the switch to the corresponding port (BQ_meas <BQ_avail, BQ _meas: bandwidth of the measured flow, BQ_avail: free bandwidth). )

In addition, the queue manager 20 protects the amount of traffic (bandwidth) not subjected to admission control when the bandwidth of the requested service is protected by the admission control, but the bandwidth of the corresponding queue is smaller than the measured bandwidth due to the malfunction. The packet may be transmitted after adjusting again. At this time, if it is difficult to forcibly adjust the bandwidth to notify the acceptance control unit 23.

4 is a flowchart illustrating an embodiment of a process for guaranteeing IPTV service quality in a network device according to the present invention.

First, as the packet classifier 21 receives the service request packet from the IPTV terminal, the packet classifier 21 detects a port number and transmits the port number to the protocol processor 22 along with the service request packet (401).

Thereafter, the protocol processor 22 detects a destination address and a source address from the service request packet received from the packet classifier 21 and transmits the destination address and the source address to the acceptance controller 23 together with the received port number (402).

Subsequently, the admission controller 23 checks the free bandwidth of the queue corresponding to the port number received from the protocol processor 22 and compares the bandwidth of the service requested by the IPTV terminal to determine whether to provide the service according to the result ( 403).

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

The present invention can be used for IPTV service and the like.

1 is a configuration diagram of an embodiment of a general IPTV service system;

2 is a configuration diagram of an embodiment of a network device having a quality guarantee function of an IPTV service according to the present invention;

3 is a diagram illustrating an embodiment of an operation of a queue manager according to the present invention;

4 is a flowchart illustrating an embodiment of a process for guaranteeing IPTV service quality in a network device according to the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS

20: queue management unit 21: packet classification unit

22: protocol processing unit 23: acceptance control unit

Claims (5)

delete delete In a network device, Queue management means for managing a spare bandwidth of a queue corresponding to each port number; Packet classification means for detecting a port number in response to receiving a service request packet from an IPTV terminal and transmitting the detected port number together with the service request packet; Protocol processing means for detecting a destination address and a source address from the service request packet received from the packet classification means and delivering the received destination number together with the received port number; And And after checking the free bandwidth of the queue corresponding to the port number received from the protocol processing means and the admission control means for determining whether to provide a service compared to the bandwidth of the service requested by the IPTV terminal, The admission control means, The network apparatus according to the following Equation A, accepts the service request from the IPTV terminal, and if not satisfied, rejects the service request from the IPTV terminal. Equation A

(Where, BQ_req: the transmission bandwidth of the request service identified in the CIT, BQ_avail: the free bandwidth of the queue, BQ_max: the maximum transmission bandwidth available in the queue,

: Bandwidth of the current reserved service of the queue, BQ_lim: minimum bandwidth for transmission of general service traffic) The method of claim 3, wherein The queue management means, Manage IPTV service traffic as the first virtual queue, manage general traffic as the second virtual queue, The admission control means, And satisfying Equation A, controlling the queue management means to limit the bandwidth of the second virtual queue as shown in Equation B below. Equation B

(Where, BQ_rate_limit: maximum transfer bandwidth limitable, B_mar: minimum free transfer bandwidth required for secure traffic control) The method of claim 3, wherein The admission control means, And determining whether Equation (A) is satisfied by using a service channel bandwidth of a channel information table (CIT).

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